Slash, the first time I did accounting was in my early 30s - long after I had finished a graduate degree in sciences and had worked for some time. It is challenging more for its boring nature rather than intellectual difficulty (at least the level encountered at an intro level). Depending on your location, your local university might offer some introductory courses and ease your way into the subject. I still have to find an interesting accounting book - I think that is an oxymoron.
BTW, CFAI books are fine too, IMO.